The disclosed embodiments of the present invention relate to noise filtering, and more particularly, to a signal processing apparatus having a sigma-delta modulating block collaborating with a notch filtering block and related signal processing method thereof.
Any unwanted signal component would be regarded as noise, which may limit the system ability to processing weak wanted signal components. In general, the noise sources may include random noise (e.g., flicker noise, thermal noise, etc.), mixer noise, undesired cross-coupling noise, power supply noise, etc. Thus, to avoid the degradation of the wanted signal components, noise suppression technique is employed. However, the additional circuit components for achieving good noise suppression, such as active filters implemented in the analog domain, generally consume a large chip area and a large current. Thus, there is a need for an innovative design which can relax the chip area and current consumption requirements.